Generally, the lens shoots just off the shoulder of the nearest character (subject) on to the face of the other and is typically coupled with a Reverse shot and seen below from Sin City (2002). One character speaks to another which sets up a new shot . These are the go-to shot for dialogue sequences but their use is fragile. Too much of the same type of shot makes the sequence feel stale. Note, in this case that we don't see an exact reverse and are shown Shellie's point of view even in a cut to Dwight. We are ERL on Shellie and look up to Dwight.
In Iron Man (2008) Tony rushes to Yinsen's side after He has found a way to allow Tony more time to get the Mark 1 armor up and running. Tony learns that Yinsen has sacrificed himself for Tony which begins a series of events that will change the billionaire's life. Here, we look up at Tony, and down at Yinsen, this is not an intentional set up of power/status, it's just a way to continue the feeling of Yinsen laying dying on the ground and Tony being over him. The two are the same size and mirror the other's composition putting them on the same level, allowing them to share a commonality. Don't get me started on the hidden meanings in these compositions...that is for a different post.
An OTS can also be used to describe a size variation between subjects as in this set from Iron Giant (1999) (See what I did there?). The Giant towers over Hogarth but the two seem to share similar cinematographic presence due to their non threatening posing.
The OTS shot does not need to be coupled with a reverse. In Jaws (1975), Chief Brody is chumming for the shark and snarking at Quint when, who should appear in the background, but the shark AKA Bruce? In this OTS, we get to see Brody at his snarkiest but also see the hugeness of the shark which stays out of focus. Had this been a dialogue shot, we may have cut to a reverse OTS off shark on to Brody as he whirls around to face the giant fish. But what gives this shot power, is how Brody looks behind him and then bolts out of shot, think about a time when you reached into a bush or cabinet and something moved and you jumped back-that is empathy. We see Brody back his way into the cabin to setup another OTS, this time with Quint in foreground and Brody taking the left side. This is a fun way to portray Brody's two antagonists surrounding him without a reverse. Note how Brody can't take his eyes off the stern where the shark was, that makes for a pretty cool eye line. "We're gonna need a bigger boat!"
Another example of not needing a reverse OTS is from Jurassic Park (1993) (see what I did here?) Grant and Lex get up close and personal with the T-Rex. This OTS describes the sheer size of the dinosaur and the utter believability of the moment. The next shot in this sequence is a profile of Grant and Lex while the T-Rex skulks into shot from the frame's left side allowing us to continue experiencing the moment in Grant's Point of view.
Wreck it Ralph (2012) employs this OTS to describe Ralph's situation. He must get the medal so he can go back to his game and get respect. But where is the medal? Way up on the top branch of a candy cane tree in the middle of a saccharine world, continue making the task harder and the story deepens.
It's not just movies that have an affinity for the OTS, great painters of the past used the OTS to bring their viewers into scene as in "Holy Week In Seville" by Jose Jimenez y Aranda (1879) All of these images are larger, just click on them as it's a crime to view the paintings below so tiny.
Edgar Degas (1874).
Sandro Symeoni, Italian illustrator's OTS.Haddon Sundblom's Coca Cola Santas used the OTS.
Ralph Mcquarie knew the power of the OTS.